Evenflo® Classic Bottles. 1, 0-3m. Slow. *Made without BPA. Micro Air Vents™ help prevent nipple collapse. 1, 0-3m. Slow flow. 2, 3-6m. Medium flow. 3, 6m+. Fast flow. Micro Air Vents™ help to prevent or reduce nipple collapse and minimize air ingestion. Classic nipples come in slow, medium and fast flow to meet your baby's changing needs. Parent link. Answers, advice, affirmation. www.evenflo.com 1-800-233-5921 8:00am - 5:00pm EST. ©2012 Evenflo Feeding, Inc.